Annotations

The data can be annotated using different types of annotations. The Annotations widget contains a list of these types (1).

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Creation and Editing Annotations

Select the annotation type of your choice from the drop-down list (1) and click on Add (2) in order to create a new one. Depending on the type of the annotation, there are different ways to create it.

Available types of annotations:

  • Point-based annotations such as labels, lines, or splines are defined by a one or multiple points in image/world space (3). The following table shows possible interactions.
  Button Modifier Key Action
Annotation creation Left   Add a new point
Right   Set a final point
Annotation editing Left   Move annotation as a whole
Control Add new points when clicked on existing point
Alt Rotate annotation
Right   Manipulate individual points
Control Removes point when clicked on existing point
  • Curved View annotations work similarly as their corresponding point-based annotations. However, they add a new view showing a dynamic curved planar reconstruction (CPR) of the parent image data along the path defined by the annotation. More information about the curved view annotations can be found in the Curved View Annotations section.
  • Special “data” annotations such as Mesh, Points, or Point Tree do not allow the user to paint the annotation but instead open a filesystem browser for the user to select a file of corresponding type. Then the software will load the selected file and display its content as surface mesh, point cloud, or tree. More information about these annotations can be found in the Data Annotations section.
  • The Plane annotation is edited using Edit Transformation and Set Dimensions dialog from the context menu.

Essential properties

The length of the point-based annotation will be shown as a label next to it (4). An annotation currently selected from the annotation widget is displayed with a thicker line (5). The checkbox next to the annotation name in the Annotations widget allows for configuring its visibility. Annotations’ names can be changed by double-clicking on it in the widget (6) while a right-click on the annotation name opens a context menu offering annotation-specific configuration options and/or processing algorithms where available (7).

Global annotation vs. annotation attached to a data

../_images/annotations-scope.png

The newly created annotation is always attached to the currently selected image in the Data widget and can only be placed in those views where the selected data is currently shown. In this case the annotation is considered to have a “parent” data. In the case that no data was selected the annotation is considered global which means that it is always visible independent of the data selection.

Depending on the scope of the annotation, its name will appear under the name of the parent data in the Annotations widget or under (Global Annotations) list (1). An annotation can be moved to a global scope when attached to a data, or it can be moved in the other direction, i.e., from global scope to a specific parent data (2).

Curved View Annotations

../_images/annotations-curved-view.png

Curved view annotations can be used to visualize curved planar reconstruction (CPR) of the parent image data along the annotation’s trajectory. For example, given a dental CT volume one could visualize a panoramic view (1) using the curved view spline (2).

The sampling direction can be changed using a direction manipulator (3) which can be opened by right-clicking on the annotation’s name and selecting Change Sampling Direction from the context menu.

Other settings are available through Curved View Settings (4) in the context menu. They allow to add orthogonal slices (5) that go along the path of the annotation. Left mouse button can be used to change the location of the slice along the annotation’s trajectory (6). Settings also allow to change the slices’ size and other properties.

It is possible to convert between regular annotations and their corresponding curved view annotations using a Curved view entry from the context menu.

Data Annotations

../_images/annotations-data-annotations.png

There are special kinds of annotations which are referred to as “data” annotations. Those are called like that because they have an underlying Data associated with them and they are used to visualize this Data. Thus, one could use this underlying data as an input to an algorithm. Right-click on the annotation name will open a context menu where available algorithms will be listed (1).

Amongst others, these annotations are Mesh, Points (or Point Cloud) and Point Tree. Most of these annotations also have Data Controllers which allow for changing the visualization settings or some other properties of the associated data (2).

In order to execute an algorithm that takes both data that is shown in the Data widget and a data that is in the Annotations widget as input, one should first attach the annotation to the parent data set (see Global annotation vs. annotation attached to a data section) and then right-click on the annotation’s name to open available algorithms.